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991.
992.
稀土对9Cr2Mo钢抗回火能力的影响 总被引:1,自引:0,他引:1
郭铁波 《哈尔滨理工大学学报》1999,4(5):98-101
通过在冷轧辊用9Cr2Mo钢中添加稀土元素,利用全自动膨胀仪研究了稀土元素对其抗回火能力的影响。试验结果证明,稀土元素对钢中碳化物的结构没有影响,但抑制了碳化物的析出过程,提高了其抗回火能力。 相似文献
993.
The addition of an aluminium and iron doping agent, bauxite red mud, has been tested with a commercial peat for thetreatment of a secondary municipal wastewater. Based on a column study, phosphorus (P) removal was raised from about17% to 21% on peat alone to over 95% with red mud treatment of peat. By this mean, the use of red muds allowed areduction of P, concentration effluent to below 0.15 mg/L. The boosting effect of red mud seemed to decrease with timeand especially with the hydraulic loading. For a hydraulic loading of 30 cm/j, P removal met govermental guidelines (t effluent < 1 mg/L) for a period of 50 days. Other classic efficiency parameters such as BOD5, COD and coliforms werenot altered by the use of the doping agent. 相似文献
994.
995.
《International Journal of Hydrogen Energy》2020,45(1):703-711
Hydrogen has been regarded as the most promising clean and renewable energy. Beside the production of the hydrogen, the separation of hydrogen is also an import issue before it can be used in fuel cells. Membrane-based separation technologies have gained considerable attentions due to its high efficiency and low energy consumption. Zeolite imidazolate framework (ZIF) membranes have drawn intense interest due to their zeolite-like properties such as permanent porosity, uniform pore size and exceptional thermal and chemical stability. It is rather challenged to prepare well-intergrown Co-based zeolitic imidazolate frameworks (ZIFs) membranes on porous α-Al2O3 tubes since Co-based ZIFs prefer to form crystals in the synthesis solution rather than grow as membrane layer on the support surface. In this work, we report the preparation of high-quality ZIF-9 membrane with high H2/CO2 selectivity and excellent thermal stability by using 3-aminopropyltriethoxysilane (APTES) as a covalent linker to modify the α-Al2O3 tube. Due to the formation of covalent bonds between APTES and ZIF-9, ZIF-9 nutrients are bound to the support surface, thus promoting the growth of dense and phase-pure ZIF-9 membrane with a thin thickness of about 4.0 μm. The gas separation performances of the ZIF-9 membrane were evaluated by single gas permeation and mixture gas separation of H2/CO2, H2/N2 and H2/CH4, respectively. The mixture separation factors of H2/CO2, H2/CH4, and H2/N2 of the ZIF-9 membrane are 21.5, 8.2 and 14.7, respectively, which by far exceeds corresponding Knudsen coefficients. Moreover, the as-prepared ZIF-9 membrane exhibits excellent stability at a relatively broad range of operating temperature, which is beneficial for the industrial application of hydrogen separation or further membrane reactor. 相似文献
996.
997.
Sarah Meister Laura Hahn Susanne Beyer Corinna Paul Sophie Mitter Christina Kuhn Viktoria von Schnfeldt Stefanie Corradini Kritika Sudan Christian Schulz Theresa Maria Kolben Sven Mahner Udo Jeschke Thomas Kolben 《International journal of molecular sciences》2021,22(22)
The aim of this study was to analyze the expression of peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RxRα), a binding heterodimer playing a pivotal role in the successful trophoblast invasion, in the placental tissue of preeclamptic patients. Furthermore, we aimed to characterize a possible interaction between PPARγ and H3K4me3 (trimethylated lysine 4 of the histone H3), respectively H3K9ac (acetylated lysine 9 of the histone H3), to illuminate the role of histone modifications in a defective trophoblast invasion in preeclampsia (PE). Therefore, the expression of PPARγ and RxRα was analyzed in 26 PE and 25 control placentas by immunohistochemical peroxidase staining, as well as the co-expression with H3K4me3 and H3K9ac by double immunofluorescence staining. Further, the effect of a specific PPARγ-agonist (Ciglitazone) and PPARγ-antagonist (T0070907) on the histone modifications H3K9ac and H3K4me3 was analyzed in vitro. In PE placentas, we found a reduced expression of PPARγ and RxRα and a reduced co-expression with H3K4me3 and H3K9ac in the extravillous trophoblast (EVT). Furthermore, with the PPARγ-antagonist treated human villous trophoblast (HVT) cells and primary isolated EVT cells showed higher levels of the histone modification proteins whereas treatment with the PPARγ-agonist reduced respective histone modifications. Our results show that the stimulation of PPARγ-activity leads to a reduction of H3K4me3 and H3K9ac in trophoblast cells, but paradoxically decreases the nuclear PPARγ expression. As the importance of PPARγ, being involved in a successful trophoblast invasion has already been investigated, our results reveal a pathophysiologic connection between PPARγ and the epigenetic modulation via H3K4me3 and H3K9ac in PE. 相似文献
998.
Joanna Gracz-Bernaciak Oliwia Mazur Robert Nawrot 《International journal of molecular sciences》2021,22(22)
Latex, a sticky emulsion produced by specialized cells called laticifers, is a crucial part of a plant’s defense system against herbivory and pathogens. It consists of a broad spectrum of active compounds, which are beneficial not only for plants, but for human health as well, enough to mention the use of morphine or codeine from poppy latex. Here, we reviewed latex’s general role in plant physiology and the significance of particular compounds (alkaloids and proteins) to its defense system with the example of Chelidonium majus L. from the poppy family. We further attempt to present latex chemicals used so far in medicine and then focus on functional studies of proteins and other compounds with potential pharmacological activities using modern techniques such as CRISPR/Cas9 gene editing. Despite the centuries-old tradition of using latex-bearing plants in therapies, there are still a lot of promising molecules waiting to be explored. 相似文献
999.
1000.
James K Holland E Katherine Kemsley Reginald H Wilson 《Journal of the science of food and agriculture》1997,75(3):391-400
The mid-infrared spectra of raspberry and strawberry purées were acquired on two Fourier-transform spectrometers. A pre-treatment procedure, involving baseline correction and area normalisation, was developed that made the spectra from the two spectrometers compatible for use in discriminant analyses. The discriminant analyses were performed by subjecting the spectra to a principal component (PC) analysis, grouping them according to fruit species and then assigning samples to the class with the closest group mean in PC space. Models using the first PC scores of the pre-treated spectra from one spectrometer were able to correctly assign the fruit species of between 91·1 and 96·4% of the pre-treated spectra of independent test sets of the other. However, the projection of the spectra from each spectrometer into the same PC space showed differences in the mean positions of equivalent groups along the second and higher PCs. Therefore, the transfer of this data set is only wholly reliable using the first PC scores. Tests with the uncorrected spectra demonstrated their incompatibility through the complete lack of overlap of equivalent fruit species groups in PC space. ©1997 SCI 相似文献